A. Field of the Invention
This invention relates generally to high voltage circuit breakers for interrupting the flow of electrical current in high voltage electrical circuits and, more particularly, to a new and improved high voltage vacuum-type circuit interrupter. As used herein, the term "high voltage" means a voltage greater than one thousand volts.
B. Description of the Prior Art
Electrical circuit breakers and, more specifically, high voltage vacuum-type circuit interrupters, are old and well known in the art. A representative example of such a circuit interrupter, as disclosed and depicted in U.S. Letters Pat. No. 4,343,030, utilizes a plurality of two, separated, transversely disposed, insulating housings to perform the function of separating a line terminal from a switch terminal. Generally speaking, high voltage vacuum-type circuit interrupters and the individual components thereof have had many varied, generally complex and expensive configurations and have been produced in accordance with generally complicated and expensive methods of manufacture and assembly. For example, illustrative methods and structures for supporting generally tubular metallic shields of vacuum-type circuit interrupters are disclosed in U.S. Letters Pat. Nos. 3,048,681; 3,048,682; 3,586,801; 3,777,089; and 4,158,911. Switch contacts for vacuum-type circuit interrupters have also been provided having an electrical contact brazed to a solid or tubular elongated stem, the outer periphery of the contact generally extending beyond the outer periphery of the stem. Furthermore, many methods have been utilized to prevent internal components of high voltage electrical devices from being damaged or destroyed due to the ingress of moisture or other environmental contaminants. For example, separately formed elastomeric or rubber diaphragms, bellows or bladders have been installed in electrical equipment to equalize the pressure within the equipment with that of the surrounding environment. Finally, as depicted in U.S. Letters Pat. No. 2,981,813, it is known to utilize a single evacuated enclosure of a vacuum switch or relay to form both the solid external electrical insulation between coaxially aligned first and second electrical terminals both disposed at one longitudinal end of the enclosure and the solid external electrical insulation between the first and second terminals and a metallic base or support for the vacuum device at its other longitudinal end.
The present invention relates to improvements in high voltage vacuum-type circuit interrupters and in their internal components and in their methods of manufacture and assembly.